1. Field of the Invention
The present invention is related to a direct-fluid-supply writing implement in which ink is stored in an ink tank and an ink occlusion body is interposed between the ink tank and a pentip. In the present invention, “front” is defined as a pentip side and “rear” is defined as an ink tank side.
2. Description of Related Art
(1) Concerning this direct-fluid-supply writing implement, for example, Japanese Utility Model Examined Publication JP-UM-Y-45-18890 discloses a writing instrument characterized in that:
an accommodation body, into which an occlusion material is charged, having a communication hole (communication tube) and a through-hole, is inserted into an upper opening portion of an ink receiving body; and
a pentip communicating with the occlusion material is provided in the communication tube and inserted into the through-hole so as to communicate the ambient air with the ink receiving body.
Although the direct-fluid-supply writing implement disclosed in JP-UM-Y-45-18890 includes a connection tube and a communication tube in the upper opening portion of the ink receiving body, the communication tube is communicated with the ambient air at all times. Therefore, when the writing instrument is put in a state in which the pentip side is maintained downward, the ambient air is continuously supplied into the ink accommodation body through the communication tube. At the same time, ink is continuously supplied from the ink receiving body to the occlusion material through the communication tube. As a result, there is a possibility that ink leaks out from the ink receiving body to the outside through the pentip side.
(2) Further, Japanese Utility Model Examined Publication JP-UM-Y-56-7504 discloses a felt pen for writing in small characters characterized in that:
an ink accommodation chamber having an ink replenishing port, to which a lid body for tightly sealing is detachably attached, is provided on one side of the inside of a container body;
an ink occlusion material accommodation chamber, which is separate from the ink accommodation chamber by a partition wall, is arranged on a forward end opening portion side of a main body being communicated with the opening portion;
a liquid absorbing material having a ventilation property, which is divided into two portions, is accommodated in the accommodation chamber;
a base portion of a pentip is held by the liquid absorbing material on the forward end opening portion side and an end face of the base portion is contacted with the liquid absorbing material on the ink accommodation chamber side;
a liquid supply hole for supplying liquid to the liquid absorbing material is formed on the partition wall;
an appropriate air supply tube is fixed and one of the end face opening portions of this air supply tube is made to come into contact with the liquid absorbing material on the main body forward end opening portion side; and
the other end face opening portion is located in the ink accommodation chamber located close to the ink replenishing port.
The direct-fluid-supply writing implement of JP-UM-Y-56-7504 described above is composed in such a manner that two liquid absorbing materials are provided and a front end face of the air supply tube is made to come into contact with a rear end face of the liquid absorbing material on the main body forward end opening portion side so that the liquid supply hole can be communicated with a rear end face of the liquid absorbing material on the ink accommodation chamber side. That is, the direct-fluid-supply writing implement of JP-UM-Y-56-7504 described above is composed in such a manner that the front end opening portion of the air supply tube and the front end opening portion of the liquid supply hole are located being separate from each other in the front and rear direction. Therefore, it is difficult to close an opening end of the air supply tube by ink which is supplied from the liquid supply hole and impregnated in the liquid absorbing material. That is, it is difficult to put the opening end of the air supply tube into a liquid-sealing state. Accordingly, it is impossible to positively stop an outflow of ink from the ink tank and an inflow of air into the ink tank, that is, it is difficult to positively replace ink with air. As a result, a surplus quantity of ink is supplied to the liquid absorbing material. Accordingly, there is a possibility that ink leaks outside from the pentip side.
Further, since the direct-fluid-supply writing implement of JP-UM-Y-56-7504 is composed in such a manner that the pentip penetrates a liquid absorbing material on the main body forward end opening portion side and comes into contact with the liquid absorbing material on the ink accommodation chamber side. Therefore, it is difficult to set a longitudinal size of the pentip at a short length. Accordingly, a manufacturing cost of the pentip is raised. Therefore, it is impossible to provide the direct-fluid-supply writing implement to a user at a low price. Further, an ink flowing-out passage from the rear end to the front end of the pentip is extended and an ink outflow property is deteriorated. Accordingly, handwriting becomes blurred. Further, handwriting tends to break.
(3) Furthermore, Japanese Utility Model Examined Publication discloses a brush type writing instrument characterized in that:
an ink adjusting tube and an ink guiding tube are concentrically arranged in a front shaft;
an intermediate core is inserted into the ink guiding tube;
a rear end of the intermediate core is inserted into an ink chamber (ink tank) and a front end is located at a rear end of the brush body while a predetermined gap is being formed;
an ink absorbing body made of porous material is attached to an annular passage between the ink adjusting tube and the ink guiding tube and on a rear end of the brush body;
density of the forward end is made to be higher than that of the other portions;
an ink passage is formed at the rear end of the brush body;
an air passage communicated with the ambient air is formed between an inner face of the front shaft and an outer face of the ink adjusting tube; and
a rear end of the air passage and a rear end of the ink adjusting tube are communicated with each other.
The direct-fluid-supply writing implement of JP-UM-Y-60-7191 described above is composed in such a manner that the ink tank and the ink absorbing body are connected with each other by only one ink guiding tube. Therefore, at the time of the initial supply of ink, that is, at the time of supplying ink from the ink tank to the liquid absorbing material for the first time, air and ink can not be quickly replaced with each other. Accordingly, it takes a pretty long period of time until the writing instrument gets ready for writing.
Further, since the number of parts of the direct-fluid-supply writing implement of JP-UM-Y-60-7191 is large and the structure is complicated, it is difficult to provide the direct-fluid-supply writing implement of JP-UM-Y-60-7191 to a user at a low price.